McCaw headache for All Blacks

Ongoing headache problems, following the concussion he suffered in the first Test against England, have forced All Black flanker Richie McCaw to withdraw from New Zealand's team for the remainder of the Tri-Nations series.

A statement from the All Black camp on Wednesday said that McCaw has been declared unavailable as he continues to "recover" from a head injury suffered against the world champions in Dunedin.

Following discussion with the All Blacks coaching and medical staff, McCaw announced his withdrawal from the squad which will allow him to focus on making a full recovery from injury, and to commence a return to rugby fitness programme.

"This is the best decision both for myself and the All Blacks," McCaw said in a statement. "I am making progress on recovering from the symptoms of the head injury, but there is the added concern of not being match fit."

McCaw will likely remain on the sidelines for the next month while he focuses on recovery and conditioning.

All Blacks doctor Graham Paterson said McCaw is continuing to make steady progress on overcoming the symptoms of post-concussion syndrome brought on by his injury.

All Blacks coach Graham Henry commended McCaw on his handling of what has been a difficult and frustrating period for the leading loose forward.

"I have been extremely impressed with the way Richie has conducted himself and responded to this challenge, and how he has continued to contribute to the team," Henry said.

The All Blacks selectors also announced that flanker Craig Newby will rejoin the Tri-Nations squad as replacement, when it assembles in Auckland on Sunday as cover for McCaw.